1. Field of the Invention
The present invention relates to an optical detecting module, and more particularly, to an optical detecting module with preferred light utilization efficiency.
2. Description of the Prior Art
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a diagram of an optical detecting module 40 in prior art. FIG. 2 is a sectional view of the optical detecting module 40 shown in FIG. 1 along line B-B. The optical detecting module 40 includes a housing 42, a light emitting component 44 and an optical detecting component 46. The light emitting component 44 and the optical detecting component 46 are disposed inside the housing 42. The light emitting component 44 is a light emitting diode (LED) with wide-angle illumination. An optical positive signal S1 of the optical detecting signal output by the light emitting component 44 is projected upward to transmit out of the housing 42, and an optical lateral signal S2 of the optical detecting signal is projected onto an inner wall of the housing 42 and does not transmit out of the housing 42. Part of the optical detecting signal emitted from the light emitting component 44 is received by the optical detecting component 46; for example, the optical detecting component 46 receives the optical positive signal S1 but cannot receive the optical lateral signal S2. In order to maintain light receiving quantity of the optical detecting component 46 exceeding a predetermined value, energy applied to the light emitting component 44 is increased to enhance illumination, which results in energy consumption and does not conform to a trend of energy conservation and environment protection.